There are many different types of material dispensers available to the market offering differing levels of automation. Choosing one type of dispenser over another is often a function of what type of material is needing to be dispensed and is further defined by the ability of the material being dispensed to flow (as in the case of a liquid—typically referred to as the materials' viscosity) or change its form (as in the case of a powder) when relieved of a means of containing such material in a cylindrical shape. A machine dispensing material low in viscosity would likely be different in both methodology and apparatus from that of a machine dispensing a more viscous paste-type material.
For purposes of background and by way of illustration, references will be made to common practices found in the ink industry because such practices fairly represent the practices found in other industries requiring the use of accurately dispensing a specific amount of material from one container to another. It should be understood that the various aspects and teachings of the inventions described herein are not limited in their application and are not limited to the ink industry. Indeed, the various aspects, teachings, embodiments and methodologies described herein have application in all industries and in all systems and processes where it is desirable to dispense a specific amount of material from one container to another.
As is known, materials are typically stored and transported by using a number of different containers. Among the most common are steel drums (55 and 30 gallon capacities), HDPE buckets (5, 3½, 2 and 1 gallon capacities), and HDPE jugs (1 gallon capacity). Other containers include cardboard-roll or plastic cylindrical tubes (5″, 3¾″ and 2″ tubes). The 5″ and 3¾″ tubes are typically known in the ink industry as being either HDPE or cardboard-roll tubes and commonly referred to as Sonoco™ or Ritter cartridges. These tubes typically hold 4.4 or 8 lbs of material. The 2″ tubes are typically known in the construction industry as being either HDPE or cardboard-roll tubes and commonly are referred to as caulk tubes that typically hold either 10 ounces or 1 quart of material. Still other known containers include metal cans of 1 and 2 quart capacities. These cans may be made of metal or have a cardboard-roll body that typically hold 1 quart of tint (or colorant) as seen in the paint industry. Still other containers include bags made from a substantially air-tight, flexible, compressible composite material.
Dispensing equipment is seen in virtually every industry requiring a finished product that is created from a formulation. Formulations are often seen in the paint, ink, cosmetics, pharmaceutical, foodservice and chemicals industries. For example, in the ink industry, a printer may need to have a custom color of ink created to satisfy the requirements of a particular project. The custom color of ink is created using a formulation, or a recipe of materials. This combination of pre-determined amounts of specific ingredients is also used in the paint industry, for example, to create a custom color of paint and in the cosmetics industry to create a custom color of facial cream or makeup base.
A current manual method for creating a custom color from a formulation in the ink industry is for the operator to manually transfer one of the formulation components from one container (such as, a 55 gallon drum, 5 or 3½, 2 or 1 gallon (plastic) bucket, or an 8 lb. metal can) into another container, which sits on a precision scale, until the operator adds enough material into the container on the scale to reach the required amount of material called-out in the formulation for that finished product. The operator repeats the process with every component required of the formulation until the operator has “weighed-up” each ingredient. Throughout the process of “weighing-up,” the operator may need to manually add to or deduct from the amount of material placed into the finished product container that sits on the scale in order to attain the target value stated for each component in the formulation. This manual method of creating finished products from a formulation through the use of a container on a scale is referred to as the “Smart Scale” or “Hand Mix” method in a number of industries (hereinafter “Manual Mix Method”).
Another current method for creating a finished product from a formulation is through the use of a dispenser that may have a number of reservoir containers, each of which would contain one of the components required to create a finished product. The component is moved from the reservoir container, through the use of a pumping device connected to the reservoir container, through a length of piping to a dispensing valve that, upon receiving feedback from a computer's controlling software (which receives feedback from a scale that the receiving container sits upon), terminates the flow of material (at a value close to the target amount) and deposits the material into a receiving container. The dispensing valve would need to repeatedly open and close upon feedback from the computer and scale in order to dispense small amounts of a component to reach the target amount. The pumps subsequently would need to push the component through the dispensing valve, which may be rapidly opening and closing. The aforementioned pumping devices typically are piston, positive displacement, gear, diaphragm or peristaltic type pumps that force the material through the piping. Each of the aforementioned pumping device types are best suited for specific applications that relate to, among other things, the viscosity of the material being moved, the volume at which the material is required to pass through it and the level of accuracy required of the pumping device for the application. The aforementioned dispensing valve may be a ball, globe, piston, diaphragm, plug or butterfly type. Each of the aforementioned dispensing valve types are best suited for specific applications that relate to, among other things, the viscosity of the material being moved, the volume at which the material is required to pass through it and the level of accuracy required of the dispensing valve for the application. This automated method of creating finished products from a formulation is often referred to as “Automated Pump Dispensers” method in a number of industries (hereinafter “Gravimetric/Pump Dispenser Method”).
Yet another current type of automated material dispenser uses a number of reservoir containers, each of which contains one of possible components required of any finished formulation and dispenses those components through a volumetric means as opposed to the aforementioned Gravimetric means. The volumetric method (hereinafter “Volumetric Dispensing Method”) uses a positive displacement means of dispensing where a cylinder, filled with a material component, is emptied of some portion of the material (that resides within it) through the use of a piston found within it (located between the material component and the discharge end of the cylinder) that moves a predetermined distance and displaces a predetermined amount of the material component. This Volumetric Dispensing Method assumes that when the piston moves a predetermined distance that the amount of material component dispensed is the same time after time.
Drawbacks and disadvantages exist with respect to the Manual Method of dispensing formulations. For example, operator handling is the most costly expense of creating custom formulations when using the Manual Mix Method. In the ink industry, for instance, 55 gallon steel drums, 5 and 3½ gallon plastic buckets and 5 lb. and 8 lb. tin buckets are the most common container types used for storage and delivery of ink, whether the material is a base component used to create a finished product or is finished ink. The operator must manually remove the component from the container through the use of a spoon or putty knife type of tool. Paste-type ink, for instance, can be extremely dense and highly viscous (4,000-40,000 cps (centipoise) where water=1 cps; honey=5,000 cps). Paste-type ink's “stringing” characteristics (the ability for the material to adhere to itself, even when attempting to be separated) are high. The process of scooping the material from the buckets is physically taxing on the operator and can be a very messy operation due to the stringing nature of the material.
In addition, the accuracy of creating a formulation using the Manual Method is a function of the resolution of the scale (how accurate the scale is (measured in a percentage of the scale's full capacity)) and of operator skill in being able to apply the appropriate amount of material needed for any given formulation. If the material is highly viscous the operator can more easily remove material from the amount added (if the amount added were too high) than if the material were less viscous in which case the material added may disperse into the material already in the receiving container, not allowing for removal of the amount over added. If too much of a given material of the formulation is manually added, additional amounts of the other components required of the formulation would proportionally need to be added, resulting in the creation of more finished product than originally requested, potentially resulting in material waste.
Similarly, there are some drawbacks and disadvantages with the Gravimetric/Pump Dispenser Method. Some of the major drawbacks experienced with this method are dispense valve actuation, dispensing time, accurate reporting, scale cost, effect of vibration and wind currents, pump wear and cost, air fluctuation, and multiple scale cost. More specifically, and by way of example, the dispense valve opens via an electric/pneumatic solenoid valve which is controlled by a Human Machine Interface (HMI) which is the layer or device that separates a human that is operating the machine from the machine itself and, in some instances, is a computer. The HMI either communicates directly with or sends signals to other devices, for example, a program logic controller (PLC) which ultimately provides control of all electrical, pneumatic and mechanical movements and actions of the machine. The HMI sends a signal to a pneumatic solenoid that then in turn sends a pneumatic (air) signal that must physically travel through an air line in order to open and/or close the dispense valve. The delay created in an air signal needing to travel through an air line to the pneumatic solenoid affects how fast the dispense valve can physically open and close. The process of the dispense valve opening and closing in order to accurately dispense a small amount of material is commonly referred to as being in “pulse mode.” Any delay of the air signal traveling through the air line will ultimately affect how long the dispense valve remains in the pulse mode. If the target weight amount is less than or equal to 0.1 grams, the importance of the dispense valve not remaining in the pulse mode becomes critical.
Another drawback involves time delays in dispensing materials. The multiple dispensing valves may need to move in and out of position to accommodate any given material needing to be dispensed. There are time added delays due to the scale needing to completely stop its movement after each dispense in order that the computer can activate the pump to dispense more product, if required. The overall formulation dispense time may therefore increase because of required accuracy or number of components. As the dispense valve opens and closes, some amount of residual liquids, in the form of a drop, can remain on the edge of the dispense valve. When the scale signals the computer that the target value has been reached the computer closes the dispense valve. The residual material can fall into the final receiving container due to gravity. The computer receives a signal that the dispense is complete and does not account for any residual material that may fall into the final dispense container. To resolve this inherent problem, some manufacturers of Gravimetric/Pump Dispensers may have their software “lock-in” the target value for reporting purposes, when in fact the actual dispensed amount may be different.
Yet another disadvantage with Gravimetric/Pump Dispensers relates to the costs of the scales needed with those systems. The scales may vary in cost between $1,500 and $10,000 per scale. Some Gravimetric/Pump Dispensers may use several scales of varying capacities that add significantly to the cost of the Gravimetric/Pump Dispenser.
In addition, scales can be susceptible to vibration and air movement due to their sensitive load cells. Scales used for dispensers are often set to read as accurately as possible. Air movement over the scale or vibration under the scale may cause the scale to interpret the movement as additional weight and relay the information to the computer. The computer may interpret that the dispense valve has added more material to the final dispense when in fact it has not. The computer, therefore, must give the scale time to stabilize before adding more product. This problem could cause time delays and inaccurate readings of the actual dispense if the scale is not shrouded by a cover.
Yet another drawback involves the pumps used with the Gravimetric/Pump Dispensers. These pumps are used to transfer material from the reservoir containers to the dispense valves. A costly pump is required for each material component. The pumps add considerable upfront expense and ongoing maintenance expenses to the system. The cost of maintenance is high due to the fact that the pumps, being mechanical devices, inherently are subject to a high degree of wear and tear. Failure of the seals that provide the pumping ability is the most common maintenance issue with pumps. The pumping system relies on compressed air supplied by the end user of the Gravimetric/Pump Dispensers. Air compressors struggle with the delivery of consistent air pressure which the dispense valve relies on to accurately dispense to the scale. If there is too much fluctuation in delivered air pressure (15-20 psi) the calibration values set in the computer may “over dispense” or “under dispense.”
Moreover, there are disadvantages and drawbacks related to the transportation, storage and disposal of known material containers. For instance, there can be high costs relating to residual waste of material in a container when the material in the container is used and the container is disposed of. Waste is also due to the material curing prior to its intended end use when, in the container, it may develop a film (often referred to as “skinning”) when exposed to certain environmental conditions. The operator may dispose of the container even though it may still have a substantial amount of material remaining in it.
Throughout the course of using any material stored in a bucket container, the bucket's lid may be removed and replaced a multiple number of times, depending on the volume requirement of that particular material for any given formulation. If all of the material in the bucket is not used when the lid is first removed, and the lid is repeatedly removed and replaced, over the course of time the material in the bucket, especially that material that may not have been sufficiently removed from the side walls of the bucket, tends to skin-over or may become crusty, rendering it useless and adding to the amount of wasted material. Occasionally, the dried or contaminated material on the sidewalls contaminates the remaining “good” material in the bottom of the bucket, rendering the good material difficult to work with, making it more subject to operator disposal. Additionally, on the bottom of a bucket, due to the bucket's construction, areas could be present where ink becomes trapped and the complete removal of the ink from the bucket becomes virtually impossible.
Similarly, throughout the course of using any material stored in a HDPE jug container, the HDPE jug container's cap may be removed and replaced a multiple number of times, depending on the volume requirement of that particular material for any given formulation. If all of the material in the HDPE jug container is not used when the cap is first removed, and the cap is repeatedly removed and replaced, over the course of time the material in the HDPE jug container, especially that material that may not have been sufficiently removed from the side walls of the HDPE jug container, tends to skin-over or may become crusty, rendering it useless and adding to the amount of wasted material. Occasionally, the dried or contaminated material on the sidewalls of the HDPE jug container contaminates the remaining “good” material in the bottom of the HDPE jug container, rendering the good material difficult to work with, making it more subject to operator disposal. Additionally, on the bottom and on the sidewalls of an HDPE jug container, due to the HDPE jug container construction and the small opening, areas could be present where ink becomes trapped and the complete removal of the ink from the HDPE jug container becomes virtually impossible.
Additionally, there are drawbacks with respect to known cardboard-roll or plastic tubes that result in material waste in those containers. The known tubes use a movable displacing “puck” that, when pressed downwards towards the bottom of the tube, acts as a plunger to press the material residing in the tube out of the orifice found on the bottom of the tube. However, with known tube designs, an area remains between the puck and the fixed end of the tube, creating a region for the material in the tube to remain and not be discharged thus creating waste when the tube is disposed of.
Other drawbacks and disadvantages exist with respect to known dispensers, material containers and dispensing methods that are overcome by the present inventions described herein.